I. Field of the Invention
This invention pertains to the field of transporting materials and, more particularly, to transporting materials by a fork-lift and push-pull type truck. This invention eliminates the pallets commonly used in the transportation cycle and provides a better and more advantageous pallet.
II. Description of the Related Art
The present invention contemplates a new and improved method and device for transporting materials which is simple in design, effective in use, and overcomes the foregoing difficulties and others while providing better and more advantageous overall results.
The world population is increasing. In fact, the UN Food and Agriculture Organization projects an increase of 5 to 7 billion people over the next 30 years. This is like adding a new China or India every 10 years.
Population increase and economic expansion consumes land for housing and infrastructure. The earth""s land and its resources are limited. Science and technology have provided us with the ability to do more while using less of the available land and resources. However, science and technology are limited as to what they can provide. Mother Earth will be stressed to keep up with world population expansion.
Quality of life is inextricably linked to the basics: reproduction, food, housing, packaging and transportation. Technology plays a major role by providing for a better standard of living for the worlds"" people. However, responsible business managers must be at the forefront of developing, providing and using environmentally responsible products.
For over sixty years products have been placed on wood pallets and we have used forklifts to load these products into trailers, containers and railcars. In today""s world of high technology this equates to farming with a pair of oxen and a shovel plow. Packaging on wooden pallets can no longer be rationalized nor can shipping the product to a customer who throws the wood pallet into a trash receptacle with the pallet ultimately ending up in a landfill. Landfills are being closed and the trees required to make a good quality wood pallet are becoming scarce thus making the wood more expensive. Today""s U.S. wood pallet average cost is over eight dollars. Landfill expense pushes the total cost of using a wood pallet to about ten dollars. This cost adds to the packaging, logistics and ultimately to the consumer""s cost of the products they purchase.
Data indicates the global market for wood pallets is in excess of one billion units annually. The data does not include remanufactured or reused pallets. This data also indicates that the U.S. uses over five hundred million wood pallets annually. About four hundred and fifteen million (83%) end up in landfills, about eighty million (16%) are recycled/reused and about five million (1%) disposed of as firewood.
One of the challenges being addressed is the depletion of the world forest to manufacture wood pallets which are then disposed into landfills. We will teach how to use commercially and economical feasible replacement products made from recycled material and/or commercially and economical feasible replacement products that can be recycled back into themselves. These products will be used as the material handling system for the 21st century.
The material handling industry is an industry seeking a change, but until now lacked an uncomplicated economical alternative to the wood pallet. The slip sheet disclosed and claimed within U.S. Pat. No. 5,613,447 and co-pending patent application, Ser. No. 08/823,698 (now U.S. Pat. No. 5,881,651) are those unpretentious economical alternatives. The use of such a slip sheet in conjunction with a captive pallet system leads the way to the future of material handling. These two items taken together, finally accomplish what so many have tried for so long to achieve.
A captive pallet system is one where the shipper and receiver use a good quality wood, plastic or metal pallet to handle the product in-house while the product is packaged on a slip sheet.
The unit of product has hereto been pulled by means of a forklift attachment called a push-pull, from the captive pallet at the point of shipment and the slip sheet becomes the article of conveyance to transfer the unit of product from the shipper to the receiver. Thus the captive pallet is kept or xe2x80x9ccapturedxe2x80x9d for reuse at the point of shipment.
At the receiving point, the product is pulled from the trailer using a push-pull attachment or a regular fork-lift truck and placed on the purchaser""s captive pallet. From that point, it is handled as a normal palletized load using a regular forklift and normal warehouse storage techniques. The shipping/receiving cycle is described in greater detail later in this application.
Both the producer and his customer keep their good quality wood, metal or plastic pallet in-house. The issue of who destroyed or damaged a $50-$200 plastic pallet, who pays for a lost pallets, cost of returning empty pallets and all the associated problems of using inferior quality wood pallets and wood pallets in general are eliminated.
The slip sheet utilized by the present invention is a product which utilizes and creates a market for virgin and/or recycled and/or off- specification polymeric material. The design of the slip sheet corrects the inherent problems of current plastic and fiber slip sheets. To teach the scope of these problems, later herein is a short synopsis of the problems associated with prior known slip sheets.
The disclosed slip sheet allows the material handling industry to adopt it as a shipping medium, currently performed by pallets. The design this slip sheet eliminates the need for a forklift attachment called a push-pull at the shipping location for many products.
The purpose of this invention is to eliminate the need for a push-pull attachment at the receiving end after product has been shipped using the disclosed slip sheet.
There are two major obstacles associated with current slip sheets. One obstacle is the occurrence of inaccessibility of the lip/tab due to crumpling during transit or shifting of the load. The other obstacle is maintenance of the product on the slip sheet in transit.
Additionally, there are related issues with current slip sheets. Product damage and/or spillage caused by the push-pull gripper jaws colliding with the packaged unit in the operators attempt to grasp the deficient lip/tab. Product damage and/or spillage caused by the push-pull gripper jaws colliding with the packaged unit during the push-pull""s jaw release and push cycle. Further, cost considerations need to be made because of the need to have a push-pull at both the shipping and receiving points to handle the current slip sheets. Also, the increasing cost of more sophisticated designed push-pull in an attempt to overcome the inadequacy of current slip sheets lip/tab and their resultant cost as a high maintenance item must be considered.
Field interviews verify that slip sheet and push-pulls in general, do not work well and exhibit these shortcomings, preventing slip sheets from enjoying a greater share of the material handling market.
One material handling area that slip sheets have made an impact is in the grocery industry. However it is one thing to shift a few hundred pound palletized unit of potatoes chips or corn flakes back unto the slip sheet and another thing to restack 2500 pounds of 40 or 80 pounds bags of salt that has shifted in transit. It should be noted that with present slip sheet design, it is only necessary that the product shift as little as xe2x85x9 inch and the lip/tab crease will be covered pushing the lip/tab tightly against the floor of the trailer/container/railcar. With certain bagged products, simply settling during transit will cause the footprint of the product to expand covering the creased area, causing it to be pushed tightly against the floor. Obviously, this creates a problem at the receiving end as it is impossible to grasp the tab/lip and the jaws and platens of the push-pull slide over the top of the product, resulting in product damage. It then become incumbent upon the receiver to unload the unit by hand with manual labor called xe2x80x9chumpingxe2x80x9d.
The technique to make the slanted lip disclosed within U.S. Pat. No. 5,881,651, was added to further enhance and ensure the ability of the lip/tab to fold-up and not crumple when units are added in-line. It was this concept that assured good presentation of the lip/tab for the push-pull""s jaws to clamp and/or make an accentuated angle so an operator could simply drop the lift trucks push-pull""s platens and/or forks and slip under the slip sheet.
By having a compressible convex airfoil-type cross-sectional area to facilitate the grasping of this type lip/tab in conjunction with the front sidewall, several of the needs of a slip sheet were met. Obviously, it was discovered this design also allowed us to employ a conventional lift truck with tapered forks, meeting several of the additional needs of the material handling industry.
In accordance with the present invention, there is disclosed a new and improved captive pallet and slip sheet combination which overcomes the problems associated with both a wood pallets transport system and a captive pallet transport system.
Further in accordance with the invention, the slip sheet of the present invention is formed from a flat sheet of material having a flat load receiving portion and four side edges. It is within the scope of the present invention to provide a slip sheet of the type disclosed in U.S. Pat. No. 5,881,651. However, it is further within the scope of the present invention to provide a slip sheet having conventional tabs, or having no tabs. Slip sheets having other designs may require the receiver to use push/pull attachments on forklifts.
Further in accordance with the invention, the captive pallet of the present invention comprises a first fork receiving area for reception of the forks of a conventional forklift for use when the captive pallet is moved, whether in a loaded or unloaded state. The captive pallet also provides a second fork receiving area for reception of the forks of a conventional forklift when it is desired to move only the load, either to load onto the captive pallet or remove from the captive pallet. Various embodiments of captive pallets are provided in the present invention, all having the common feature of providing first and second fork receiving areas. When the captive pallet is engaged on a ground surface in position for normal usage, the second fork receiving area is located higher from the ground surface than the first fork receiving area. The first fork receiving area is characterized by the presence of at least one upper barrier member against which the forks abut when the captive pallet is raised off the ground by the action of the associated forklift. The second fork receiving area is characterized by the absence of any upper barrier. The captive pallet further includes a plurality of planar load supporting surfaces adjacent the second fork receiving areas.
Further in accordance with the invention, there is provided a method of transporting materials. The method includes utilization of a captive pallet and slip sheet combination. A captive pallet having a first fork reception area adapted for use with the forks of an associated forklift. The captive pallet further includes a second fork reception area adapted for use with the forks of an associated forklift. An unloaded captive pallet may be properly positioned for reception of a load by placing the forks of an associated forklift into the first fork receiving area, raising the captive pallet from its resting position, transporting the captive pallet to a load receiving area, and lowering the captive pallet to the ground (or loading platform, etc). A slip sheet may then be positioned onto the load supporting surfaces. A load of material may be placed onto the load receiving portion of the slip sheet. The material may be secured to the slip sheet by any means known in the art such as binding, shrink wrapping and the like. The combination of loaded slip sheet and the captive pallet may be transported to another area by utilizing the associated forklift and the first fork receiving areas as discussed above. In order to move only the loaded slip sheet, the forks of the associated forklift are inserted into the second fork receiving areas. Upward movement of the forks cause the forks to abut the underside of the slip sheet and lift it off the captive pallet.